Intelligent wastewater treatment in the metal-processed industry

Before pressed and bent steel rims go into the paintwork, they are rinsed and degreased. This produces wastewater. However, the wastewater quantities and qualities from industrial processes are usually fluctuated. At one of the leading manufacturers of steel rims for cars and trucks, HST has redesigned and implemented a new wastewater treatment plant for three different types of wastewater streams. The required wastewater data for the dimensioning of the system technology was collected during the preparation of a water and wastewater balance by HST. The data of the secondary streams were called by the production plant. From this, HST, in cooperation with the personnel of the affected production departments, came up with proposals to reduce the use of water.

The main stream with about 280 m³ per day forms the wastewater from the paint and product cleaning. A side stream from the laundry of air purification with about 5 m³ per day and resulting emulsions with about 10 m³ per day were integrated into the treatment solution. By separation, water contained in the emulsions is separated off. After pretreatment of the effluents from the paint and product cleaning they are fed to the air washing, which further treated by means of multi-stage precipitation and flocculation. Accumulating sludge is drained by a chamber filter press and can be disposed of properly. Through intensive and open communication between operating staff of the wastewater treatment plant and the production plant, the wastewater treatment plant can now be optimally operated.